PathTable ReadPathTable(BasicVolumeDescriptor descriptor, Endian endian)
{
Assert.IsNotNull(descriptor, nameof(descriptor));
Assert.IsTrue(endian == Endian.BigEndian || endian == Endian.LittleEndian, "Endian must be set to either little or big.");
if (endian == Endian.BigEndian)
{
Reader.Position = descriptor.TypeMPathTableLocation * DefaultSectorSize;
}
else
{
Reader.Position = descriptor.TypeLPathTableLocation * DefaultSectorSize;
}
var buffer = Reader.ReadBytes((Int32)descriptor.PathTableSize);
var pathtable = new PathTable(endian);
for (var offset = 0; offset < buffer.Length;)
{
var namelength = buffer[offset + 0];
var extendedsectors = buffer[offset + 1];
var sector = BinaryIO.ReadUInt32FromBuffer(buffer, offset + 2, endian);
var parentindex = BinaryIO.ReadUInt16FromBuffer(buffer, offset + 6, endian);
var name = Encodings.ASCII.GetString(buffer, offset + 8, namelength).Trim(' ');
pathtable.Items.Add(new PathTableItem(name, sector, parentindex));
offset += MathUtil.RoundUp(8 + namelength, 2);
}
return(pathtable);
}
/// <summary>
/// Reads a <see cref="DirectoryRecord" from a buffer./>
/// </summary>
/// <param name="buffer">The buffer to read from.</param>
/// <param name="offset">The offset in the buffer to read from.</param>
/// <returns></returns>
DirectoryRecord ReadDirectoryRecord(Byte[] buffer, Int32 offset)
{
Assert.IsNotNull(buffer, nameof(buffer));
var length = (Int32)buffer[offset];
var record = new DirectoryRecord();
record.ExtendedAttributeRecordLength = buffer[offset + 1];
record.SectorNumber = BinaryIO.ReadUInt32FromBuffer(buffer, offset + 2);
record.DataLength = BinaryIO.ReadUInt32FromBuffer(buffer, offset + 10);
record.RecordingDateAndTime = ReadDirectoryRecordDateTime(buffer, offset + 18);
record.Flags = (DirectoryRecordFlags)buffer[offset + 25];
record.FileUnitSize = buffer[offset + 26];
record.InterleaveGapSize = buffer[offset + 27];
record.VolumeSequenceNumber = BinaryIO.ReadUInt16FromBuffer(buffer, offset + 28);
var textlength = buffer[offset + 32];
record.FileIdentifier = Encodings.ASCII.GetString(buffer, offset + 33, textlength).Trim(' ');
var num2 = ((textlength & 1) == 0) ? 1 : 0;
var num3 = textlength + num2 + 33;
var num4 = length - num3;
if (num4 > 0)
{
record.SystemUseData = new Byte[num4];
Array.Copy(buffer, offset + num3, record.SystemUseData, 0, num4);
}
return(record);
}
/// <summary>
/// Reads the <see cref="VolumeDescriptor"/> at the current position of the image file.
/// </summary>
/// <returns>The <see cref="VolumeDescriptor"/> located at the current file position.</returns>
VolumeDescriptor ReadVolumeDescriptor()
{
var buffer = Reader.ReadBytes(DefaultSectorSize);
var type = (VolumeDescriptorType)buffer[0];
if (type == VolumeDescriptorType.Primary)
{
var descriptor = new BasicVolumeDescriptor();
descriptor.VolumeDescriptorType = type;
descriptor.StandardIdentifier = Encodings.ASCII.GetString(buffer, 1, 5);
descriptor.VolumeDescriptorVersion = buffer[6];
descriptor.SystemIdentifier = Encodings.ASCII.GetString(buffer, 8, 32).Trim(' ');
descriptor.VolumeIdentifier = Encodings.ASCII.GetString(buffer, 40, 32).Trim(' ');
descriptor.VolumeSpaceSize = BinaryIO.ReadUInt32FromBuffer(buffer, 80, Endian.LittleEndian);
descriptor.VolumeSetSize = BinaryIO.ReadUInt16FromBuffer(buffer, 120, Endian.LittleEndian);
descriptor.VolumeSequenceNumber = BinaryIO.ReadUInt16FromBuffer(buffer, 124, Endian.LittleEndian);
descriptor.LogicalBlockSize = BinaryIO.ReadUInt16FromBuffer(buffer, 128, Endian.LittleEndian);
descriptor.PathTableSize = BinaryIO.ReadUInt32FromBuffer(buffer, 132, Endian.LittleEndian);
descriptor.TypeLPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 140, Endian.LittleEndian);
descriptor.OptionalTypeLPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 144, Endian.LittleEndian);
descriptor.TypeMPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 148, Endian.BigEndian);
descriptor.OptionalTypeMPathTableLocation = BinaryIO.ReadUInt32FromBuffer(buffer, 152, Endian.BigEndian);
descriptor.RootDirectory = ReadDirectoryRecord(buffer, 156);
descriptor.VolumeSetIdentifier = Encodings.ASCII.GetString(buffer, 190, 128).Trim(' ');
descriptor.PublisherIdentifier = Encodings.ASCII.GetString(buffer, 318, 128).Trim(' ');
descriptor.DataPreparerIdentifier = Encodings.ASCII.GetString(buffer, 446, 128).Trim(' ');
descriptor.ApplicationIdentifier = Encodings.ASCII.GetString(buffer, 574, 128).Trim(' ');
descriptor.CopyrightFileIdentifier = Encodings.ASCII.GetString(buffer, 702, 37).Trim(' ');
descriptor.AbstractFileIdentifier = Encodings.ASCII.GetString(buffer, 739, 37).Trim(' ');
descriptor.BibliographicFileIdentifier = Encodings.ASCII.GetString(buffer, 776, 37).Trim(' ');
descriptor.CreationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 813);
descriptor.ModificationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 830);
descriptor.ExpirationDateAndTime = ReadVolumeDescriptorDateTime(buffer, 847);
descriptor.EffectiveDateAndTime = ReadVolumeDescriptorDateTime(buffer, 864);
descriptor.FileStructureVersion = buffer[881];
return(descriptor);
}
if (type == VolumeDescriptorType.SetTerminator)
{
var descriptor = new SetTerminatorVolumeDescriptor();
descriptor.VolumeDescriptorType = type;
descriptor.StandardIdentifier = Encodings.ASCII.GetString(buffer, 1, 5);
descriptor.VolumeDescriptorVersion = buffer[6];
return(descriptor);
}
throw new Exception();
}